The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
The driving assemblies for the aircrafts generally include a nacelle forming a generally circular outer envelope, comprising inside a turbojet engine disposed along the longitudinal axis of said nacelle. The turbojet engine accommodates the fresh air coming from the upstream or front side, and rejects from the downstream or rear side the hot gases coming from the combustion of the fuel, which give a certain thrust.
The bypass turbojet engines exhibit around this turbojet engine of the fan blades generating a significant secondary cold air flow along an annular flow path passing between the motor and the nacelle, which adds a high thrust.
Some nacelles include a thrust reverser system which closes at least partially the annular cold air flow path, and rejects the secondary flow forward in order to generate a braking thrust of the aircraft.
A known type of thrust reverser, shown in particular by the document FR-A1-2758161, includes rear movable cowls called “trans-cowls” axially sliding rearwards under the effect of cylinders by deploying flaps in the annular flow path in order to close the most part of this flow path. The flaps radially return the cold air flow outwardly by passing through the cascades uncovered by the movable cowls during their sliding, comprising blades which direct this flow forward.
Furthermore some nacelles include a rear secondary nozzle called a “Variable Fan Nozzle” (VFN), providing a variable secondary flow due to a translation movement of the control system of this nozzle which is connected to the movable cowls of the thrust reverser by guide means allowing an axial movement.
A known system for actuating the thrust reverser as well as the variable secondary nozzle, includes cylinders bearing on the fixed front structure in order to, firstly slide the secondary nozzle rearwards, then when it abuts on its guide means connected to the movable cowls of the thrust reverser, secondly to drive these movable cowls which are open rearwards.
A problem with this actuating system is that the cylinders must include a significant stroke, representing the sum of the stroke of the secondary nozzle and the movable cowls. These cylinders are then difficult to design because of their length, to resist in particular to the bending, the buckling and the fatigue behavior.
Furthermore, the significant length of the cylinders makes their integration complicated into the front portion of the nacelle dedicated to the equipment, while avoiding the areas including risks of projections in the case of the bursting of the turbine.